A disturbance in auditory perception is expressed in a decrease in the ability of the hearing organs to detect, recognize and perceive speech. Hearing loss (ICD code 10 H90) refers to partial hearing loss, while a complete loss of hearing ability is called deafness.
The loss of their functions by the hearing organs can develop under the influence of both endogenous and exogenous factors. However, in the end, such a process leads to a violation of auditory perception, when a person can not hear and distinguish speech. Hearing impairment complicates the communication process and significantly impairs the quality of human life.
Diagnostic method
The evoked potentials of the brain are a modern way of testing the performance and functioning of various analyzers, including auditory ones in the cerebral cortex. This diagnostic method makes it possible to record the responses of auditory analyzers to the effects of external artificially created stimuli.
How is fixation done?
The process of fixing evoked auditory potentials occurs through microelectrodes, which are connected directly to the nerve endings of a certain area of the cerebral cortex. The sizes and diameter of microelectrodes do not exceed one micron, which explains their name. Devices are straight rods consisting of a high-resistance insulated wire with a sharp end of the recorder. The microelectrode is fixed and connected to the amplifier of the received signal. The information received is displayed on the monitor screen and is reflected in the data on the magnetic tape.
Non-invasive method
The described method belongs to the category of invasive. However, there is also a non-invasive method for obtaining auditory evoked potentials. In this case, the electrodes are not passed through the cells of the cerebral cortex, but are attached to the neck, knees, body and scalp.
Classification of responses
Diagnosis through evoked auditory potentials allows you to study the functioning of the sensory systems of the brain, as well as mental processes. Responses received in response to the effects of an artificial stimulus are usually classified according to their arrival rate at:
- Short latent - up to 50 milliseconds.
- Medium latent - 50-100 milliseconds.
- Long latent - more than 100 milliseconds.
Acoustic auditory evoked potentials arise as a result of stimulation of the auditory cortex by sound clicks occurring alternately. Sound is delivered first to the patient’s left ear, and then to the right. The speed of signal reception is reflected on a special monitor, on the basis of which the decoding of the obtained indicators is carried out.
Auditory and visual potentials allow you to diagnose and confirm damage to the optic nerves and tracts, as well as damage to the hearing organs, both central and peripheral.
Often, the method is used to test hearing in children as the most reliable in identifying the pathological process.
Tinnitus as a sign of auditory impairment
Many people wonder why it makes noise in the ears and what to do.
Such a common symptom, also called tinnitus, is not an independent pathology, but only indicates the presence of diseases of the acoustic system or hearing organs. Experts believe that tinnitus may be signs of the following diseases:
- Arterial hypertension or hypotension.
- Osteochondrosis localized in the cervical region.
- Inflammation in the ear, including otitis media.
- Hearing loss (ICD code 10 H90) of the sensorineural type.
- Meniere's disease.
- Vascular atherosclerosis.
- State of stress.
- Pathologies of the thyroid gland, diabetes mellitus and other diseases of the endocrine system.
- Multiple sclerosis.
- Taking certain medications, including diuretics, Aspirin, antibiotics, tricyclic antidepressants, etc.
- Acoustic injury.
Why noise in the ears and what to do, it is important to find out in a timely manner.
Most diseases can be diagnosed through evoked potentials. It is necessary to identify the cause of tinnitus, since the treatment and the effectiveness of the therapeutic measures will depend on this. Among the causes of tinnitus, a special place is occupied by auditory nerve neuroma, the symptoms and treatment of which we will consider in detail below.
Neuroma: Description
The disease is a neoplasm of a benign type. The diagnosis of auditory nerve neurinoma is made in every tenth case of the appearance of tumors in the brain. The neoplasm is not prone to malignancy and metastasis and in general is not dangerous to human life. Not in all cases the decision is made on the surgical removal of the tumor. If it ceases to progress and grow, the choice is made in favor of expectant tactics.
The reasons for the development of auditory nerve neuroma are well understood. Most often, along with neuroma, a neurofibromatosis of the second type is fixed, when a patient regularly and inexplicably develops benign tumors in the nervous system. By the end of life, this pathology provokes a complete loss of vision and hearing.
Most often, neurinoma occurs in the fair sex. There are no preventative measures for this disease, the patient is required to carefully consider his own health and consult a doctor at the first sign of hearing impairment.
Stages
Neurinoma develops in stages, like any tumor neoplasm. Pathology goes through the following stages:
- The first is characterized by the size of the tumor, not exceeding two centimeters. The disease takes place in a latent form and can manifest as motion sickness in transport, as well as dizziness of an unexplained genesis.
- The second stage is accompanied by the growth of the tumor up to three centimeters and the first pronounced signs of the disease, the patient has asynchronous movements, facial distortion, a sharp decrease in speech perception by ear, as well as visual impairment.
- The third stage is recorded when the tumor reaches a size of more than four centimeters. It becomes difficult for the patient to move smoothly, strabismus and impaired auditory function and visual impairment are observed.
Symptoms of Neuroma
Signs of neurinoma appear in stages, depending on the progress of tumor growth and the stage of its development. The most characteristic symptoms of an auditory nerve tumor are:
- Decreased quality of auditory perception. This is the first and very important symptom of the disease. Hearing impairment is mild and not always seen by the patient. A person may complain of hum and tinnitus, which is a reaction of the cochlea and the auditory nerve to squeezing them with a growing tumor.
- Dizziness. Most often noted simultaneously with a decrease in listening perception. This is due to the pressure of the neoplasm not only on the nerve responsible for the hearing, but also on the one that is responsible for the vestibular apparatus. After dizziness, a vestibular crisis can follow, accompanied by nausea and vomiting, pain in the head, chaotic horizontal eye movements, which are already detected during diagnostic measures.
- Soreness and parasthesia. At the initial stage of the development of neurinoma, the patient feels numbness of part of the face, as well as goosebumps and tingling, reminiscent of the situation after a long stay in a static position. After the pain syndrome manifests itself, characterized by dull and aching pains, which the patient may take for dental or caused by neuralgic disorders. Over time, the pain syndrome assumes a permanent character and radiates to the occipital region, in the direction on which the neurinoma is detected.
- Paresis. Occurs when squeezing an overgrown facial neuroma. With paresis, the affected area slows down movement, a person expresses emotions with effort, in some cases the symptom is accompanied by paralysis. In addition, part of the tongue loses its sensitivity, which leads to increased salivation.
- Weakness of the muscles responsible for chewing food. It appears simultaneously with paresis. In some cases, complete atrophy of the masticatory muscles occurs.
Symptoms and treatment of auditory nerve neuromas are interrelated.
Further symptoms depend on the direction in which the neurinoma grows. If the tumor grows back and up, the cerebellum is compressed. In this case, it becomes difficult for the patient to move smoothly, it is difficult to maintain one position for a long time and maintain balance. When the neurinoma grows back and down, the vagus and glossopharyngeal nerves are compressed . This leads to difficulties in pronouncing sounds, swallowing, and loss of sensation in the back of the tongue. In some cases, speech function is completely lost, the affected area of the tongue atrophies.
At the last stage of damage to the auditory nerve, intracranial pressure rises, which causes a violation of visual perception, blind spots appear in several areas. In addition, vomiting of unknown origin appears, pain in the head, concentrated in the occipital or frontal part of the head. Pain medications, as a rule, can not cope with pain.
Therapy
Timely treatment will prevent the effects of neuroma. Therapy in the later stages may be accompanied by complications in the form of damage to the facial nerve, hearing or paralysis of the facial muscles.
Where to buy a hearing aid? This is a common question. About it further.
The treatment of neurinoma is carried out by several methods that can be combined or interchanged in the absence of the effect of therapy.
Expectant Tactics
If neurinoma of the auditory nerve does not show a tendency to grow and was detected by chance, a decision on its surgical removal is not made. The specialist prescribes regular visits and examinations several times a year. If the tumor has not grown over two years, an examination begins every year or if signs of progress are detected. In addition, wait-and-see tactics are chosen in the case of the elderly patient, since the operation in this case is life-threatening. Even in the case of slow tumor growth, the specialist often decides to wait. To reduce the intensity of the symptoms manifested, the patient is prescribed painkillers and anti-inflammatory drugs, as well as diuretics to relieve swelling.
Radiation therapy
It is prescribed in case of contraindications for surgical intervention or when the neurinoma is small and can be destroyed under the influence of radiation. The procedures are carried out by the course, while even if the tumor is not completely destroyed, it can decrease and stop growth.
Surgical removal of this pathological tumor
If after irradiation the tumor begins to grow in size, and the patient’s body allows the operation, the doctors decide on the surgical removal of the neurinoma. The procedure is performed under general anesthesia. In the future, antibiotics are prescribed to prevent infectious complications.
Total recovery after removal of the tumor can reach one year. In the hospital, the patient after the operation will spend at least two weeks. In some cases, relapse of the neuroma is not ruled out when tumor cells remain in the patient’s body.
Hearing aid
If hearing is irrevocably lost or partial impairment of speech perception is observed, wearing a hearing aid may be recommended to the patient. Where to buy it? The device is made to order in specialized clinics or stores, taking into account the diagnosis and degree of hearing damage.
In childhood, it is very important to diagnose hearing impairment on time, since timely detection will help to avoid complications in the future life of the child. Today, there are quite a few modern and non-invasive methods for detecting auditory disorders, which are widely used in medical practice.
We examined what evoked potentials are.